1. Field of the Invention
The present invention relates to a toner image carrying member, such as an electrophotographic photosensitive member and an intermediate transfer member, and a method for manufacturing the toner image carrying member, and an electrophotographic apparatus having the toner image carrying member.
2. Description of the Related Art
There are various types of so-called electrophotographic apparatuses, that is, image forming apparatuses employing an electrophotographic system. Directing attention to the transfer method employed, for example, there are electrophotographic apparatuses employing a method in which a toner image is transferred directly from an electrophotographic photosensitive member to a transfer material (such as paper and OHT) or those employing a method (intermediate transfer method) in which a toner image is primarily transferred from an electrophotographic photosensitive member to an intermediate transfer member, and then secondarily transferred from the intermediate transfer member to a transfer material.
A significant problem arising in connection with electrophotographic apparatuses is how to reliably clean away (remove) toner (hereinafter referred to as “transfer residual toner”) that remains on an outer peripheral surface of a toner image carrying member such as an electrophotographic photosensitive member and an intermediate transfer member without being transferred (including both primary transfer and secondary transfer).
As a method for cleaning transfer residual toner from an outer peripheral surface of a toner image carrying member, there is known one in which the transfer residual toner is removed by scraping off with a cleaning blade put on the outer peripheral surface of the toner image carrying member (hereinafter referred to as “blade cleaning method”). As a technique to achieve improved cleaning performance in the blade cleaning method, for example, JP 10-142956 A discloses a technique of making the ten-point average roughness of the surface of the intermediate transfer member be not larger than 3.5 μm.
However, when the inventors of the present invention conducted a cleaning performance test by using in combination the blade cleaning method and an intermediate transfer member (an intermediate transfer belt) shaped into an endless belt and whose outermost layer (the layer nearest to the outer peripheral surface) was formed through dip coating and whose outer peripheral surface had a ten-point average roughness of 0.1 μm, the cleaning blade got entangled in the rotating intermediate transfer belt during the test, resulting in damage.
That is, while the cleaning blade can remove transfer residual toner in a favorable manner when a toner image carrying member such as an intermediate transfer member is formed to have an outer peripheral surface that is highly smooth, such an arrangement also involves a problem in that the cleaning blade becomes more liable to be entangled in the toner image carrying member that is rotating.
In particular, when the outermost layer of the toner image carrying member is formed as a coating layer (layer formed through coating of a coating liquid), depending on the physical property of the coating liquid, the outermost layer surface, that is, the outer peripheral surface of the toner image carrying member may become extremely smooth, and the cleaning blade becomes more liable to be entangled in the toner image carrying member more for that.